This invention relates generally to a container for transporting bulk goods and, more particularly, to a transportable container comprising a flexible bag for receiving particulate fill material and a spirally wound overwrap for stabilizing the bag.
Typical containers utilized for transport of bulk particulate fill material are inefficient, do not have a very large volume, and often require a large amount of manual labor be used in filling and handling of the container. Also these containers are typically stacked on top of each other during handling and transport, because the containers are not stabilized, this results in damage to the material.
Johnstone et al. discloses in U.S. Pat. No. 5,566,530 method for packaging of irregularly shaped articles, flowable granules, or liquids comprising placing an open framework on a pallet to create a space. The space is filled with the material and then a stretch wrap film is wrapped around the material and the framework. Finally the framework is removed from the film.
Williamson discloses in U.S. Pat. No. 4,113,146 a container comprising a spirally wound film to form an inner container, this is surrounded by a middle layer of spirally wound polyester filament, which is in turn surrounded by an single outer wrap sheet. The ends of the inner container are closed with ties and a support sling is located between the middle and outer layers. In U.S. Pat. No. 4,253,507 Williamson discloses a two ply inner tube covered by an over wrap that is bonded to the inner tube. One end of the inner tube is folded and sealed to form a closed bag like structure.
In U.S. Pat. No. 3,374,599 Sanders discloses a method comprising dropping the materials into a container mounted to a conveyor, placing a continuous tubular thermoplastic netting around the container, sealing one end of the netting, then dropping the netting and material out of the container onto a second conveyor where the other end of the netting is sealed. The netting may subsequently be heated to form a firmer package.
In U.S. Pat. No. 5,353,936 Dockstader et al. discloses a protective tray for use in forming a palletized load of stacked bags of particulate material. The protective tray comprises double wall corrugated cardboard or rigid plastic and in a preferred embodiment it is surrounded by a stretch wrap that encircles the protective tray and the bags.
Connolly discloses in U.S. Pat. No. 4,136,501 a system comprising wrapping a palletized load with a sheet of thermoplastic netting material. Finally, Humphrey discloses in U.S. Pat. No. 4,299,076 a system for wrapping a stabilizing overwrap around a load mounted on a pallet, which is placed on a rotating turntable. The overwrap has a width that is equal to the height of the load and with each rotation the overwrap undergoes successive increasing stages of tension and stretch.